THE SHOW | THE MICROTECHNOLOGY INFORMATION PORTAL
23.02.2026
C - Automation
From leather belts to high-tech drives
The automatic turning machines industry places the highest demands on people, machines – and every single component in the production process. Especially with sliding headstock automatic lathes, the reliability of the drive system is a decisive factor in determining system availability, process stability and cost-effectiveness. One central element that is often underestimated is the flat belt.
Dipl. Ing. Werner Graf AG has been involved in the development and optimisation of flat belt solutions for decades – and can look back on a long technical evolution.
A look back: the predecessors of today's high-performance belts
1939 – Solutus VP 06 E / LP 06 E
The first flat belts for use in precision mechanics were made of fleece and leather materials and were manufactured as endless loops.
With thicknesses of 1.2 mm and 2.0 mm, they were designed for the ‘classic’ oily drives of the time. Despite their robustness, these belts increasingly reached their limits with increasing speeds, load changes and continuous operation.
1954 – Hevaloid 525 / 535
A significant technological leap followed with the introduction of rubber belts made of CR (chloroprene).
The endless vulcanised design, combined with a hardness of 70 ShA and thicknesses of 1.5 mm and 2.0 mm, brought decisive advantages:
- significantly higher flexibility
- very smooth running
- improved service life compared to leather and fleece belts
These belts shaped the use of conventional automatic lathes for decades.
The customer's situation
An international manufacturer of high-quality precision turned parts continues to rely on state-of-the-art CNC machines as well as proven conventional sliding head automatic lathes such as Tornos TV, T, M4 and M7 for large-scale production.
The high quality of the products is closely linked to maximum plant availability. Unplanned downtime has a direct impact on delivery dates, cost structure and internal planning processes.
This was precisely where the challenge lay:
Premature belt failures repeatedly led to unplanned maintenance and service calls. Despite intensive efforts by various manufacturers, the desired service life optimisation could not be achieved. The search for a sustainable solution ultimately led the company to the engineering team at Dipl. Ing. Werner Graf AG.
The task: a flat belt for extreme conditions
The company was looking for a flat belt that could withstand the special requirements of the bar turning industry over the long term:
- Extreme oil resistance
- Smooth running, even at high speeds
- High resistance to load changes
- Maximum service life with minimum maintenance
Particular attention was paid to a known weak point in previous solutions.
The challenge in detail
The most common cause of failure in existing flat belt drives was not the belt material itself, but the adhesive or composite joint.
Under the influence of oil, temperature and dynamic load changes, this connection came loose during operation in an uncontrolled manner, leading to sudden machine downtime – with all the known consequences.
For the engineering team, one thing was clear:
A real improvement was only possible with a completely redesigned, endless belt concept.
The solution: Hevaloid V 11185 – the modern high-performance belt
The result of intensive development work is the Hevaloid V 11185:
- Material: NBR rubber (nitrile rubber), blue
- Hardness: 75 ShA
- Thickness: 1.8 mm
- Design: endless, without adhesive or weak points
Thanks to the excellent oil and media resistance of NBR, the optimised hardness and the endless production, the belt impresses with:
- exceptional service life
- high dimensional and running stability
- consistently smooth running even during continuous operation
- significantly reduced maintenance and downtime costs
Conclusion
The development of the Hevaloid V 11185 impressively demonstrates how targeted material selection, decades of experience and practical engineering can work together. For the bar turning industry, this represents a decisive step towards greater process reliability, higher productivity and long-term cost-effectiveness.